如何在Flutter的ListView中添加复选框？

bzzcjhmw 于 2023-02-05 发布在 Flutter

关注(0)|答案(3)|浏览(148)

我已经采取了下面的代码从How to create a checkbox using listview检查所有的项目时，一个项目被选中。我如何修复代码不检查所有的项目？

class CheckBoxInListView extends StatefulWidget {
  @override
  _CheckBoxInListViewState createState() => _CheckBoxInListViewState();
}

class _CheckBoxInListViewState extends State<CheckBoxInListView> {
  bool _isChecked = false;

  List<String> _texts = [
    "InduceSmile.com",
    "Flutter.io",
    "google.com",
    "youtube.com",
    "yahoo.com",
    "gmail.com"
  ];

  @override
  Widget build(BuildContext context) {
    return ListView(
      padding: EdgeInsets.all(8.0),
      children: _texts
          .map((text) => CheckboxListTile(
                title: Text(text),
                value: _isChecked,
                onChanged: (val) {
                  setState(() {
                    _isChecked = val;
                  });
                },
              ))
          .toList(),
    );
  }
}

flutter

来源：https://stackoverflow.com/questions/63788530/how-to-add-checkbox-in-listview-in-flutter

3条答案

按热度按时间

c8ib6hqw1#

只需创建一个'_isChecked'变量的列表并使用它。

class CheckBoxInListView extends StatefulWidget {
  @override
  _CheckBoxInListViewState createState() => _CheckBoxInListViewState();
}

class _CheckBoxInListViewState extends State<CheckBoxInListView> {
  List<String> _texts = [
    "InduceSmile.com",
    "Flutter.io",
    "google.com",
    "youtube.com",
    "yahoo.com",
    "gmail.com"
  ];

  List<bool> _isChecked;

  @override
  void initState() {
    super.initState();
    _isChecked = List<bool>.filled(_texts.length, false);
  }

  @override
  Widget build(BuildContext context) {
    return ListView.builder(
      itemCount: _texts.length,
      itemBuilder: (context, index) {
        return CheckboxListTile(
          title: Text(_texts[index]),
          value: _isChecked[index],
          onChanged: (val) {
            setState(
              () {
                _isChecked[index] = val;
              },
            );
          },
        );
      },
    );
  }
}

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frebpwbc2#

你应该有一个被选中的列表，并将它们分别分配给每个项目。

class CheckBoxInListView extends StatefulWidget {
  @override
  _CheckBoxInListViewState createState() => _CheckBoxInListViewState();
}

class _CheckBoxInListViewState extends State<CheckBoxInListView> {
  final List<SimpleModel> _items = <SimpleModel>[
    SimpleModel('InduceSmile.com', false),
    SimpleModel('Flutter.io', false),
    SimpleModel('google.com', false),
    SimpleModel('youtube.com', false),
    SimpleModel('yahoo.com', false),
    SimpleModel('gmail.com', false),
  ];

  @override
  Widget build(BuildContext context) => ListView(
        padding: const EdgeInsets.all(8),
        children: _items
            .map(
              (SimpleModel item) => CheckboxListTile(
                title: Text(item.title),
                value: item.isChecked,
                onChanged: (bool val) {
                  setState(() => item.isChecked = val);
                },
              ),
            )
            .toList(),
      );
}

class SimpleModel {
  String title;
  bool isChecked;

  SimpleModel(this.title, this.isChecked);
}

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kmbjn2e33#

得票最多的答案会进行更正，报告两个错误、已更正的错误和行：
1.类型为“bool？”的值不能赋给类型为“bool”的变量。更正：_isChecked[索引] =值！;
1.必须初始化不可为null的示例字段“_isChecked”。更正：延迟列表已检查;

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